Field of the Invention
The present invention relates to object hierarchies and more particularly to the visual presentation of a structured collection of objects in a graphical user interface (GUI).
Description of the Related Art
Electronic objects in a data processing system often are organized hierarchically in a parent-child relationship. Specifically, the earliest file systems for computing environments provided a hierarchical directory structure in which electronically stored documents could be stored in specific directories or folders. Directories and folders, collectively viewed as containers, could be nested to provide a level of organization for electronic documents akin to a tree having a root node, leaf nodes and intermediate branches and connecting nodes.
Contemporary data structure theory expands upon the notion of the hierarchical directory structure to provide the most common form of genus-species data organization not only for file storage, but for general objects in memory as well. While hierarchical trees are known to be constructed programmatically in a number of ways, the most common way is the linked list of nodes in a tree formation. Generally, the hierarchical tree can be visually rendered in a GUI by providing collapsible nodes such that the hierarchy can be viewed merely as a root node, or the hierarchy can be viewed in fully expanded form to reveal the hierarchical tree. Of course, as each node in the hierarchy can be expanded or collapsed individually, any portion of the hierarchical tree can be viewed within the GUI is most computing users have become accustomed to understand.
While the conventional hierarchical tree structure has proven quite effective in illustrating one-dimensional parent-child relationships among stored objects in a structured collection, the modern GUI is at a loss to illustrate multidimensional relationships in a structured collection of objects. Yet, many stored objects enjoy multi-faceted relationships including, not only parent-child relationships, but also membership and access privileges relationships, date, time and place relationships, related resources relationships, and alerts, notifications and alarms relationships. For example, a structured collection of tasks in an activity not only can include an ordering of tasks and nested sub-tasks, but also the structured collection of tasks can be viewed from the perspective of users permitted access to modify certain tasks, resources required to complete certain tasks, or dates, times and places for performing certain tasks.
Recognizing the multidimensional nature of structured collections of objects, conventional solutions propose the juxtaposition of different hierarchical trees within a GUI to provide different views of the structured collection, where each hierarchical tree is of only one dimension of interest. For example, in U.S. Pat. No. 6,151,024 to Alimpich et al. for DATA PROCESSOR CONTROLLED DISPLAY INTERFACE WITH TREE HIERARCHY OF ELEMENTS VIEW EXPANDABLE INTO MULTIPLE DETAILED VIEWS, upon selection of a parent object in a tree hierarchy, the child objects for the parent are displayed in multiple, different views in separate screen regions in order to display attributes of one of the different types of child objects.
The type of solution provided by Alimpich et al. is also apparent in U.S. Pat. No. 6,281,896 to Alimpich et al. for DATA PROCESSOR CONTROLLED DISPLAY INTERFACE WITH TREE HIERARCHY OF ELEMENTS VIEW EXPANDABLE INTO MULTIPLE DETAILED VIEWS, in U.S. Pat. No. 6,647,394. to Herzberg et al. for DOING BUSINESS EMPLOYED LINKED TREES HAVING RETRIEVABLE EMBEDDED INFORMATION, and in U.S. Pat. No. 6,842,176 Sang'udi et al. COMPUTER RELATED METHOD AND SYSTEM FOR CONTROLLING DATA VISUALIZATION IN EXTERNAL DIMENSION(S). In all such cases, however, separate views are provided for each dimension resulting in a cluttered screen and incoherent presentation for the end user.